Split L3 Cache Topology Awareness in CPU Manager

[sphrasavath]

Enhancement Description

• One-line enhancement description (can be used as a release note):
  We proposed this KEP to introduce a new CPU Manager static policy option that makes best effort to align CPU resources by L3 (last-level) cache.
• Kubernetes Enhancement Proposal: https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/4800-cpumanager-split-uncorecache/README.md (original in https://docs.google.com/document/d/1LpnMjGNsQyHOuVHMktIrjZsdRw9aKZ8djt354nAno6M/edit?usp=sharing) Previous issue Enhance CPU manager with L3 cache aware #2621
• Discussion Link:
• Primary contact (assignee): @sphrasavath, @wongchar, @ajcaldelas
• Responsible SIGs: Node
• Enhancement target (which target equals to which milestone):
  • Alpha release target (x.y): 1.32
  • Beta release target (x.y): 1.33
  • Stable release target (x.y): 1.35
• Alpha
  • KEP (k/enhancements) update PR(s): KEP-4800: Split UnCoreCache awareness #4810
  • Code (k/k) update PR(s): Split L3 Cache Topology Awareness in CPU Manager kubernetes#126750
  • Docs (k/website) update PR(s):

Please keep this description up to date. This will help the Enhancement Team to track the evolution of the enhancement efficiently.

[kannon92]

Are you all going to update the KEP? That link is old so I'm not sure your design still applies?

[kannon92]

/sig node

[kannon92]

First thing, please create a KEP PR where you fill in the template.

https://docs.google.com/document/d/1LpnMjGNsQyHOuVHMktIrjZsdRw9aKZ8djt354nAno6M/edit?usp=sharing

Does not suffice as a design doc.

[ffromani]

First thing, please create a KEP PR where you fill in the template.

https://docs.google.com/document/d/1LpnMjGNsQyHOuVHMktIrjZsdRw9aKZ8djt354nAno6M/edit?usp=sharing

Does not suffice as a design doc.

@sphrasavath Please make sure to use the very latest KEP template (just use the tip of the main branch), the template changes over time.
I agree there are more details to be filled, most of them the KEP template will make explicit.

[haircommander]

/assign @sphrasavath @wongchar @ajcaldelas

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In response to this:

/assign @sphrasavath @wongchar @ajcaldelas

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[haircommander]

/milestone v1.32
/label lead-opted-in

[impact-maker]

Hello @haircommander @sphrasavath 👋, v1.32 Enhancements team here.

Just checking in as we approach enhancements freeze on 02:00 UTC Friday 11th October 2024 / 19:00 PDT Thursday 10th October 2024.

This enhancement is targeting for stage alpha for v1.32 (correct me, if otherwise).

Here's where this enhancement currently stands:

• KEP readme using the latest template has been merged into the k/enhancements repo.
• KEP status is marked as implementable for latest-milestone: v1.32.
• KEP readme has up-to-date graduation criteria.
• KEP has submitted a production readiness review request for approval and has a reviewer assigned.
• KEP has a production readiness review that has been completed and merged into k/enhancements. (For more information on the PRR process, check here). If your production readiness review is not completed yet, please make sure to fill the production readiness questionnaire in your KEP by the PRR Freeze deadline on Thursday 3rd October 2024 so that the PRR team has enough time to review your KEP.

For this KEP, we would need to update the following:

• KEP has a production readiness review that has been completed and merged into k/enhancements.

The status of this enhancement is marked as at risk for enhancement freeze. Please keep the issue description up-to-date with appropriate stages as well. Thank you!

If you anticipate missing enhancements freeze, you can file an exception request in advance. Thank you!

[chanieljdan]

Hi @sphrasavath 👋, 1.32 Release Docs Lead here.

Does this enhancement work planned for 1.32 require any new docs or modification to existing docs?

If so, please follows the steps here to open a PR against dev-1.32 branch in the k/website repo. This PR can be just a placeholder at this time and must be created before Thursday October 24th 2024 18:00 PDT.

Also, take a look at Documenting for a release to get yourself familiarize with the docs requirement for the release.

Thank you!

[wongchar]

@chanieljdan created draft PR in k/website dev-1.32 for this enhancement. Docs in progress.
kubernetes/website#48340

[ajcaldelas]

Hello @haircommander @sphrasavath 👋, v1.32 Enhancements team here.

Just checking in as we approach enhancements freeze on 02:00 UTC Friday 11th October 2024 / 19:00 PDT Thursday 10th October 2024.

This enhancement is targeting for stage alpha for v1.32 (correct me, if otherwise).

Here's where this enhancement currently stands:

• KEP readme using the latest template has been merged into the k/enhancements repo.
• KEP status is marked as implementable for latest-milestone: v1.32.
• KEP readme has up-to-date graduation criteria.
• KEP has submitted a production readiness review request for approval and has a reviewer assigned.
• KEP has a production readiness review that has been completed and merged into k/enhancements. (For more information on the PRR process, check here). If your production readiness review is not completed yet, please make sure to fill the production readiness questionnaire in your KEP by the PRR Freeze deadline on Thursday 3rd October 2024 so that the PRR team has enough time to review your KEP.

For this KEP, we would need to update the following:

• KEP has a production readiness review that has been completed and merged into k/enhancements.

The status of this enhancement is marked as at risk for enhancement freeze. Please keep the issue description up-to-date with appropriate stages as well. Thank you!

If you anticipate missing enhancements freeze, you can file an exception request in advance. Thank you!

@impact-maker I think we do have the prod-readiness merged already can we consider this checked marked as well?

[rytswd]

Hi @sphrasavath @wongchar @ajcaldelas 👋 -- this is Ryota (@rytswd) from the v1.32 Communications Team!

For the v1.32 release, we are currently in the process of collecting and curating a list of potential feature blogs, and we'd love for you to consider writing one for your enhancement!

As you may be aware, feature blogs are a great way to communicate to users about features which fall into (but not limited to) the following categories:

• This introduces some breaking change(s)
• This has significant impacts and/or implications to users
• ...Or this is a long-awaited feature, which would go a long way to cover the journey more in detail 🎉

To opt in to write a feature blog, could you please let us know and open a "Feature Blog placeholder PR" (which can be only a skeleton at first) against the website repository by Wednesday, 30th Oct 2024? For more information about writing a blog, please find the blog contribution guidelines 📚

Tip

Some timeline to keep in mind:

• 02:00 UTC Wednesday, 30th Oct: Feature blog PR freeze
• Monday, 25th Nov: Feature blogs ready for review
• You can find more in the release document

Note

In your placeholder PR, use XX characters for the blog date in the front matter and file name. We will work with you on updating the PR with the publication date once we have a final number of feature blogs for this release.

[BenTheElder]

/retitle Split L3 Cache Topology Awareness in CPU Manager
[This is a Kubernetes Enhancement by definition of being an issue in this repo]

[wongchar]

@rytswd We intend to create a blog to showcase the performance improvement of using this new feature. Please add us to the list! :)
Created a draft PR here:
kubernetes/website#48579

[rytswd]

@wongchar Amazing, thanks for the update! 🥳
I have added the draft PR in our tracking board!

[tjons]

Hey again @haircommander @sphrasavath 👋 v1.32 Enhancements team here,

Just checking in as we approach code freeze at 02:00 UTC Friday 8th November 2024 / 19:00 PDT Thursday 7th November 2024 .

Here's where this enhancement currently stands:

• All PRs to the Kubernetes repo that are related to your enhancement are linked in the above issue description (for tracking purposes).
• All PR/s are ready to be merged (they have approved and lgtm labels applied) by the code freeze deadline. This includes tests.

For this enhancement, it looks like the following PRs are open and need to be merged before code freeze (and we need to update the Issue description to include all the related PRs of this KEP):

• Split L3 Cache Topology Awareness in CPU Manager kubernetes#126750

Additionally, please let me know if there are any other PRs in k/k not listed in the description or not linked with this GitHub issue that we should track for this KEP, so that we can maintain accurate status.

The status of this enhancement is marked as at risk for code freeze.

If you anticipate missing code freeze, you can file an exception request in advance. Thank you!

[tjons]

Hello @haircommander @sphrasavath 👋, Enhancements team here.

With all the implementation(code related) PRs merged as per the issue description:

• Split L3 Cache Topology Awareness in CPU Manager kubernetes#126750

This enhancement is now marked as tracked for code freeze for the 1.32 Code Freeze!

Please note that KEPs targeting stable need to have the status field marked as implemented in the kep.yaml file after code PRs are merged and the feature gates are removed.